More acidic, less fertile and less oxygen-rich: Effects of climate change on the Mediterranean Sea

Acidification, depletion of oxygen, nutrients and planktonic microorganisms at the base of food chains. Phenomena that would shape the Mediterranean Sea at the end of this century, according to a new study by the National Institute of Oceanography and Experimental Geophysics - OGS - in collaboration with the Euro-Mediterranean Centre Foundation on Climate Change - CMCC. The study was recently published in Biogeoscience.

The research assesses the impact of climate change on Mediterranean marine ecosystems in the mid to late 21st century using high-resolution projections of the physical and biogeochemical state of the basin. The research group analysed the response of Mediterranean marine ecosystems to two different CO2 emission scenarios.

The worst-case scenario simulates an uninterrupted rise in atmospheric CO2 concentrations to as high as 1200 parts per million (ppm) by the end of the century. The most optimistic scenario foresees a reduction in emissions and thus a stabilisation of CO2 levels in the atmosphere around 500 ppm. The two climate simulations confirm and extend the results already produced in recent years by the OGS marine systems modelling group and foresee a Mediterranean Sea that becomes warmer and is characterised by a general decrease in nutrient and oxygen levels in the surface and middle layers of the hips. In addition, the water column will become more acidic due to the uptake of CO2 from the atmosphere, which is consistent with projections on a global scale.
A result that supports the idea that reducing CO2 emissions would effectively mitigate the effects of climate change.